scholarly journals Atomic manipulation of in-gap states in the β−Bi2Pd superconductor

2021 ◽  
Vol 104 (4) ◽  
Author(s):  
Cristina Mier ◽  
Jiyoon Hwang ◽  
Jinkyung Kim ◽  
Yujeong Bae ◽  
Fuyuki Nabeshima ◽  
...  
Keyword(s):  
Atomic Manipulation ◽  
Gap States

scholarly journals Defect Processes in Halogen Doped SnO2

2021 ◽  
Vol 11 (2) ◽  
pp. 551
Author(s):  
Petros-Panagis Filippatos ◽  
Nikolaos Kelaidis ◽  
Maria Vasilopoulou ◽  
Dimitris Davazoglou ◽  
Alexander Chroneos
Keyword(s):  
Electronic Properties ◽  
Tin Oxide ◽  
Density Functional ◽  
Structural Changes ◽  
High Dielectric Constant ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
High Dielectric ◽  
Gap States

In the present study, we performed density functional theory calculations (DFT) to investigate structural changes and their impact on the electronic properties in halogen (F, Cl, Br, and I) doped tin oxide (SnO2). We performed calculations for atoms intercalated either at interstitial or substitutional positions and then calculated the electronic structure and the optical properties of the doped SnO2. In all cases, a reduction in the bandgap value was evident, while gap states were also formed. Furthermore, when we insert these dopants in interstitial and substitutional positions, they all constitute a single acceptor and donor, respectively. This can also be seen in the density of states through the formation of gap states just above the valence band or below the conduction band, respectively. These gap states may contribute to significant changes in the optical and electronic properties of SnO2, thus affecting the metal oxide’s suitability for photovoltaics and photocatalytic devices. In particular, we found that iodine (I) doping of SnO2 induces a high dielectric constant while also reducing the oxide’s bandgap, making it more efficient for light-harvesting applications.

scholarly journals Photoelectronic Properties of End-bonded InAsSb Nanowire Array Detector under Weak Light

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiaomei Yao ◽  
Xutao Zhang ◽  
Tingting Kang ◽  
Zhiyong Song ◽  
Qiang Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Cooling System ◽  
Variable Temperature ◽  
Light Trapping ◽  
Nanowire Array ◽  
Infrared Light ◽  
Laser Source ◽  
Array Detector ◽  
Weak Light ◽  
Gap States

AbstractA simple fabrication of end-bonded contacts InAsSb NW (nanowire) array detector to weak light is demonstrated in this study. The detector is fabricated using InAsSb NW array grown by molecular beam epitaxy on GaAs substrate. The metal-induced gap states are induced by the end-bonded contact which suppresses the dark current at various temperatures. The existence of the interface dipole due to the interfacial gap states enhances the light excitation around the local field and thus upgrades the photoresponsivity and photodetectivity to the weak light. The light intensity of the infrared light source in this report is 14 nW/cm2 which is about 3 to 4 orders of magnitude less than the laser source. The responsivity of the detector has reached 28.57 A/W at room temperature with the light (945 nm) radiation, while the detectivity is 4.81 × 1011 cm·Hz1/2 W−1. Anomalous temperature-dependent performance emerges at the variable temperature experiments, and we discussed the detailed mechanism behind the nonlinear relationship between the photoresponse of the device and temperatures. Besides, the optoelectronic characteristics of the detector clarified that the light-trapping effect and photogating effect of the NWs can enhance the photoresponse to the weak light across ultraviolet to near-infrared. These results highlight the feasibility of the InAsSb NW array detector to the infrared weak light without a cooling system.

Gap states and recombination processes in one-dimensionally ordered and disordered a-Si : H/a-Si1−xNx:H multilayer films

1987 ◽  
Vol 97-98 ◽  
pp. 931-934 ◽  
Author(s):  
M. Yamaguchi ◽  
H. Ohta ◽  
C. Ogihara ◽  
H. Yokomichi ◽  
K. Morigaki ◽  
...  
Keyword(s):  
Multilayer Films ◽  
Recombination Processes ◽  
Gap States

Effect of high-temperature annealing on the distribution of GAP states in aSi:C:H

1991 ◽  
Vol 80 (6) ◽  
pp. 383-385
Author(s):  
A.S. Volkov ◽  
H. Herremans ◽  
W. Grevendonk ◽  
V. Baptist ◽  
S.V. Chernyshov ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Annealing ◽  
Gap States

Evaluation of Sub-Gap States in Amorphous In-Ga-Zn-O Thin Films Treated with Various Process Conditions

2014 ◽  
Vol 1633 ◽  
pp. 55-60 ◽  
Author(s):  
Kazushi Hayashi ◽  
Aya Hino ◽  
Hiroaki Tao ◽  
Yasuyuki Takanashi ◽  
Shinya Morita ◽  
...  
Keyword(s):  
Thin Films ◽  
Peak Position ◽  
Process Conditions ◽  
Charge Densities ◽  
Capacitance Voltage ◽  
Time Regime ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Gap States ◽  
Capacitance Transient

ABSTRACTIn the present study, the sub-gap states of amorphous In-Ga-Zn-O (a-IGZO) thin films treated with various process conditions have been evaluated by means of capacitance-voltage (C-V) characteristics and isothermal capacitance transient spectroscopy (ICTS). It was found that the space-charge densities of the a-IGZO decreased as the oxygen partial pressure was increased during the sputtering of a-IGZO thin films. The ICTS spectra for the 4, 8, and 12 % samples were similar and the peak positions were found to be around 1 × 10-2 s at 180 K. On the other hand, the peak position for the 20 % sample shifted to a longer time regime and was located at around 2 × 10-1 s at 180 K. The total densities of the traps for the 4, 8, and 12 % samples were calculated to be 5−6 × 1016 cm-3, while that for 20 % was one order of magnitude lower than the others. From Thermal desorption spectrometer, it was found that desorption of Zn atoms started at a temperature higher than 300 °C for the 4 % sample, while desorption of Zn was not observed for the 20 % sample. The introduction of the sub-gap states could be attributed to oxygen-rich and/or Zn-deficient defects in the a-IGZO thin films formed during thermal annealing.

Dynamics of photoinduced gap states and self-trapped excitons in MX chain compounds with degenerate and nondegenerate CDW ground states

1997 ◽  
Author(s):  
Hiroshi Okamoto ◽  
Yusei Kaga ◽  
Yasuo Oka ◽  
Masahiro Yamashita ◽  
Tadaoki Mitani
Keyword(s):  
Ground States ◽  
Chain Compounds ◽  
Gap States
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